Assume <em>R</em> is measured in meters (m) and <em>M</em> in kilograms (kg). Then
<em>R</em> ² / (<em>GM</em>) = [m]² / ([N•m²/kg²] [kg]) = m•kg / N = m•kg / (kg•m/s²) = s²
so <em>t</em> ² is indeed proportional to <em>R</em> ²/(<em>GM</em>).
I think it’s 82747 on top of 827483
